| 摘要 |
PURPOSE:To enable a highly purified copper material to obtain and a copper wire for soft bonding wire to manufacture by a method wherein a highly purified electrolytic copper, which is obtained by repeating electrolytic refining in several times, is subjected to refining process by means of zone melting. CONSTITUTION:Electrolytic re-refining (the primary refining process) is performed regarding a rough copper plate of electrolytic copper as anode and the first type OFC copper foil plate as seed, and an electrolytic re-refined copper i.e. high purity electrolytic copper is obtained. By repeating electrolytic refining in several times, impurities are removed especially Fe and Ni, etc., consequently, a zone melt copper is obtained by repeating in three times refining process of high purity electrolytic copper which is subjected to electrolytic re-refining by zone melting (the secondary refining, process). Purity is more than 99.999% of copper wire in such a way, therefore the obtained material is very soft. |
